Today, enterprises of all sizes, from small retailers to giant banks, use transaction processing to control and manage the vital functions of their businesses. In the context of transaction processing, an application program may be used to implement a particular business function, for example, a payroll application or an order entry application. Commercial application programs typically process many similar items, for example, orders in an order processing system, seat reservations in an airline booking system, or credit queries in a credit control system.
In a transaction processing system, one execution of an application program usually processes a single transaction. End users have on-line access to the system and to enterprise data, and directly initiate transactions. In a transaction processing environment, many users repeatedly process similar transactions, and require a fast response to each transaction. Examples of such users are order entry clerks, airline reservation clerks, and bank tellers. Transaction processing systems are also referred to as online transaction processing systems (OLTPs).
Typically, a transaction results in one or more postings. Each posting is encoded using one or more predefined codes that specify the posting, such as a business area code, asset code, cost center code, order code, or profit center code. If the code entered by a user is invalid, the respective postings have to be corrected in retrospect. This may require reversing the incorrect postings and generating corrected postings. Such a correction may be extremely costly in terms of the data processing resources required for the reversing and correcting of postings. In particular, this may negatively impact response times of the transaction processing system, especially if the correction is to be performed while the loading of the transaction processing system is high.